This invention relates to air compressors, and more particularly to cooling and noise reduction systems for air compressors.
Air compressors commonly generate a significant amount of undesirable noise. Because of the undesirable level of noise created by a compressor, it is often necessary to provide a separate room near a work shop or job site to house the compressor. The cost of providing a separate room for the compressor can be substantial. In other arrangements air compressors are provided with enclosures, but to ensure the reliability of an air compressor in all environments, it is also important that an adequate supply of cool ambient air is properly routed through the compressor enclosure and into key areas of the compressor. The operating requirements of the compressor are directly related to how well heat is transferred from the compressor components to the ambient air. The design and layout of the compressor must ensure that a sufficient amount of cool ambient air is available for all of the components of the compressor. However, inlets and outlets that allow ambient air to pass through the compressor housing also allow noise to leave the compressor housing. There is a trade off between providing a sufficient cooling air flow through the compressor enclosure, and allowing compressor noise to exit the compressor enclosure.
The invention relates to a cooling system and noise reduction system of an air compressor unit that compresses air to pressures above normal atmospheric pressures. The air compressor unit includes an enclosure that houses the compressor components. A partition is provided to at least partially separate the interior of the enclosure into two separate compartments: a discharge compartment, and a component compartment. A compressor is disposed within the component compartment. Air flow is provided into the component compartment, and air then flows into the discharge compartment. The discharge compartment has a discharge aperture that permits air to exit the enclosure. An aftercooler is disposed within the enclosure, and may separate the discharge compartment from the component compartment. The aftercooler may be disposed between and separate the compressor and the discharge aperture.
An additional partition may be provided to further separate the component compartment into two separate compartments: a first compartment and a second compartment. The compressor is disposed within the first compartment, and a motor is disposed within the second compartment. A passage in the partition permits cooling air flow from the first compartment to the second compartment.
The enclosure also has a compressor air flow inlet that is in fluid flow communication with the first compartment, and a motor inlet that is in fluid flow communication with the second compartment. The inlets permit cooling air to enter the first compartment and the second compartment of the enclosure. The partition also has a first passage that permits cooling air to flow from the first compartment to the second compartment, and a second passage that permits cooling air to flow from the second compartment to the discharge compartment. A blower moves cooling air into the inlets, and a shroud covers the blower. A screen permits air to enter the shroud.
The arrangement of the invention provides adequate cooling air flow through the unit while also reducing the amount of noise that emanates from the air compressor unit by limiting the amount of noise exiting the enclosure in a direct xe2x80x9cline of sightxe2x80x9d path. Sound generally emanates outwardly from a noise source in a relatively straight line, or a xe2x80x9cline of sightxe2x80x9d path. The sound may reflect off a surface, but reflected noise is reduced in the arrangement of the invention by employing the use of an acoustic foam on surfaces of the enclosure to inhibit the reflection of sound.
By using acoustic foam, and reducing the direct xe2x80x9cline of sightxe2x80x9d path of the noise, the noise emanating from the unit is reduced. The direct path xe2x80x9cline of sightxe2x80x9d is broken up by creating multiple compartments and compartments in the enclosure, and having the cooling air and noise flow in a serpentine path through the compartments. The air flow path reduces the amount of direct xe2x80x9cline of sightxe2x80x9d noise that emanates from the enclosure, and permits adequate cooling air flow.
The discharge aperture is the largest opening in the enclosure, and is the primary location where noise can exit the enclosure. Noise may also exit the enclosure through the inlets and the shroud. The primary noise sources in the unit are the compressor and the motor. The discharge compartment separates the discharge aperture from the noise sources, and inhibits noise from travelling in a direct path from the noise source to the discharge aperture. Noise is prevented from directly reaching the discharge aperture by the partition and baffles. The unit may also contain the primary noise sources in additional separate compartments, which further reduces the amount of noise that emanates from the enclosure.